Activity Series of Metals Lab

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Grade 11 Chemistry
Activity Series of Metals Lab
Problem: What is the order of reactivity of the metals copper, iron, magnesium, and zinc in single
displacement reactions?
Materials:
 Wellplate/Spotplate
 Small pieces of magnesium, iron, zinc and copper metal
 Dilute solutions of hydrochloric acid, copper (II) sulfate, zinc chloride, magnesium chloride, iron (III)
sulfate
 Wash bottle with distilled water
Safety:
 Wear goggles.
 Hydrochloric acid is corrosive.
 Dispose of chemicals in the waste beaker.
Procedure:
1. Record the appearance of each metal.
2. Using the well plate, combine each type of metal with each solution and with water. Put enough drops of
the appropriate solution to completely cover the piece of metal.
3. Record any changes in appearance due to a chemical reaction. In reactions of metal with acid, look
carefully for the formation of bubbles. If you are unsure about any observations, repeat the experiment in a
small test tube. This allows you to better observe the reaction. Look for colour changes on the surface of
the shiny part of the metal or in the solution. Remember that some reactions are slow (take a long time) and
you need to carefully observe them.
5. Clean all spot plates and test tubes and repeat Steps #1 and #2 for each of the other three metals. When
finished, you will have attempted 20 different reactions (20 trials)
6. Dispose of the solutions in the waste beaker supplied by the teacher. Do not pour anything down the
drain.
Observations:
For each single displacement reaction, make your observations in the chart below. If you believe that a
reaction has occurred, write “R” on the observation chart. If you believe that no reaction has occurred, write
“NR” on the observation chart
H2O (cold and
HCl(aq)
CuSO4 (aq)
ZnCl2(aq)
MgCl2(aq)
FeCl3(aq)
distilled)
Cu
Zn
Mg
Fe
NR
NR
NR
-bubbles
formed
NR
NR
-bubbles
formed
-fizz
-heat
-change of
color –
darkened of
iron over 24
hours
NR
- change of
color
- minor
bubbling
-bubbles
formed
-reaction
highly
exothermic
-brown black
residue on
surface of
metal
Blue colour
of copper (II)
sulfate
appears to
fade
-whitish grey
precipitate
- brittle –
powdery
-Iron appears
to dissolve
NR
NR
NR
-bubbles
formed
-bubbles
formed
-exothermic
- fizz
-heat
NR
-change of
color
-bubbles
formed
-fizz
NR
Analyze and Interpret
1. a) Write a chemical equation for each single displacement reaction recorded in your observation
table. Include the predicted placement of lithium in your ranking.
b) Rank the metals you tested in order of reactivity, beginning with the most reactive metal. Include
lithium in your ranking.
Keep in mind that hydrogen is a diatomic element.
***If no reaction occurs, write NR. Use the chart provided below or develop one of your own.
Metals that displace other metals)
Mg + ZnCl2 -> MgCl2 + Zn
3Mg + 2FeCl3 -> 3MgCl2 + 2Fe
Mg + CuSO4 -> MgSO4 + Cu
Zn + CuSO4 -> ZnSO4 + Cu
3Zn + 2FeCl3 -> 3ZnCl2 + 2Fe
Fe + CuSO4 -> FeSO4 + Cu
Or
2Fe + 3CuSO4 -> Fe2(SO4)3 + 3Cu
Metals that Displace
hydrogen from acids
Metals that displace
hydrogen from cold
water
Zn + 2HCl -> ZnCl2 + H2
n/a (lithium however
should and to a
small extent maybe
magnesium)
Mg + 2HCl -> MgCl2 + H2
Fe + 2HCl -> FeCl2 + H2
Or
2Fe + 6HCl -> 2FeCl3 + 3H2
Activity Series
(list metals below)
Most Reactive
(rank)
Li
Mg
Zn
Fe
Cu
Least Reactive
The reactivity of the metals in decreasing order would be lithium, magnesium, zinc, iron, and
copper. Lithium would be the most reactive metal because it can react with water and
magnesium can’t. Magnesium is second highest because it reacted with every compound
except for water. Zinc is lower than magnesium because no reaction occurred between zinc and
magnesium chloride. Zinc is higher than iron because zinc reacted with iron (lll) chloride, but
iron did not react with zinc chloride. Copper is the least reactive metal because it did not react
with any of the compounds. This means that copper would be below all other metals in the
activity series.
1. Lithium metal reacts with water.
a) Is lithium more or less reactive than magnesium?
Yes, lithium is more reactive the magnesium because its above magnesium on the activity
series.
b) Write a balanced chemical equation to represent the reaction of lithium and water.
2Li(s) + H2O(l) -> Li2O(s) + H2(g)
c) Would the resulting product be acid or basic? How can you hypothetically test if it was an acid
or base? (suggest at least 2 different ways)
The product is an acid because it is an aqueous solution containing hydrogen ions.
Therefore, we would predict its PH to be less than 7 and can verify this using a pH meter or
a pH natural or universal indicator. To test the acidity of the product, you can use litmus
paper to test the pH level of the solution or add a known base and see if it reacts and
neutralizes – creating a salt and water. if you use red litmus paper in a product if it turns
blue then it is a base, if you use blue litmus paper in a product and it turns red, then it is an
acid. You can also use a Phenolphthalein, if it is an acid it would remain colourless, if it is a
base it would turn a pink or violet colour. A Bromothymol blue is also available, if it is tested
in a base it’ll remain blue, if it is tested in an acid it’ll turn yellow.
2. Explain how the activity series can be used to predict single displacement reactions. Consult your
textbook.
The activity series can be used to predict the occurance of single displacement reactions by
analyzing which elements are more reactive or less reactive than others. Morea reactive
elements on the activity series would displace another element below of it. The activity
series for metals as well as a noble gases have been explored. Understanding if a reaction
would occur would allow for construction of safe building materials, building tools and
operational machinery, just to name a few.
3. Given that lithium reacts with water and that magnesium does not, do you expect lithium to react
with hydrochloric acid? If so, write a balanced chemical reaction.
Yes, Lithium will react with hydrochloric acid. It will strip the electron e from
hydrogen atom. 2Li + 2HCl (aq) → H2 + 2LiCl
4. Many people use copper piping to route water through their homes. Explain why magnesium or
aluminum could not be used.
People choose to use copper piping to route water through their homes because copper does
not react with the water or acid residues contained in the pipes (i.e. resistant to corrosion).
Copper is lower in the activity series than hydrogen, making it less reactive, therefore it wouldn’t
be a single displacement reaction. If the pipes were made of Magnesium and aluminum (both
more reactive metals) it would be significantly more dangerous. Magnesium burns in steam
to produce white magnesium oxide and hydrogen gas. Pure magnesium can also
react with water to produce magnesium hydroxide which is insoluble in water and
would clog the pipes and potentially lead to high pressure area with hydrogen buildup, potentially a flood or fire hazard (since hydrogen gas is highly flammable).
Magnesium will do this since its higher than hydrogen in the activity series, and would create a single
displacement reaction. Aluminum would create Aluminum hydroxide as well as hydrogen gas, resulting in a
similar scenario as would magnesium. This makes it unsafe to route water to homes, since aluminum and
magnesium would react, where as it is safe to use copper since it is less reactive than hydrogen and below it on
the activity series. Copper is also a very ductile metal and has very good heat and electrical conductivity. Also,
copper is soft and easily bent.
5. From the following displacement reactions, arrange these hypothetical
chemicals in order of decreasing activity (most to least reactive):
A + B+  A+ + B (Since A displaces B, this indicates that A > B)
C + B+  no reaction (Since there is no reaction, B >C)
D + C+  D+ + C (Since D displaces C, D >C)
F + G+  no reaction (Since there is no reaction, G >F)
A + F+  no reaction (Since there is no reaction, F >A)
F + D+  F+ + D (F displaces D, therefore F>D)
D + B+  no reaction (no reaction means B>D)
G + A+  G+ + A (G displaces A, therefore G>A)
Most reactive to least reactive:
G> F>A>B>D>C
6. Did you see bubbles produced during any of the reactions? From your balanced chemical
equations, you can see that gas is not a product in all of these single displacement reactions. What
would account for the presence of bubbles?
Bubbles suggest that there may have been another reaction taking place within the solution.
The bubbles were more visible and bigger in the reactions that took place with magnesium, the
most reactive of the elements we used in the lab. The formation of bubbles is an indication of the
chemical reaction taking place. When the bubbles stop, it is an indication that the chemical reaction
has finished.
The bubbles are accounted from the magnesium granules being forced to react with the solvent
(water) causing hydrogen to be displaced. Since the magnesium granules were very small, it had a
large available surface area which increased the virulence of the reaction with the metal salt as well
as the solvent itself. Since the metal salt did not contain the hydrogen, the hydrogen gas produced
must be a result of magnesium extracting the hydrogen from a water molecule. . Since magnesium
primarily reacts with hot water and steam, which it was able to do by the already exothermic nature of
the reaction with the metallic salt. This hot water (which was in small volume) was easily generated
by the exothermic and vigorous reaction of magnesium and zinc chloride or iron (III) chloride.
For example:
Primary reaction:
magnesium turnings are added to a solution of iron(III) chloride.
Mg(s) + Fe3+(aq) => Mg2+(aq) + Fe2+(aq)
Seocndary reaction:
magnesium + water ==> magnesium hydroxide + hydrogen
Mg(s) + 2H2O(l) ==> Mg(OH)2(aq/s) + H2(g)
As more heat is generated in the reaction, the magnesium hydroxide and hydrogen gas are
genererated a bit faster..
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